Hi you, if you took the step from cubase 7 to cubase 8 by buing an upgrade (and not an additional full license) you can of course NOT sell the cubase 7 license and Keep the 8!
Actually if your dongle Shows the cubase 8 license you will still be able to use cubase 7 with it. But only you with your dongle.
If you bought a second license, you would have two full licenses on your dongle. Transferring this by selling is explained in Detail in the Support area. There is no “deletion” involved´that you had to do in advance.
Yeah, actually I have both licences as 7 and 8 separately. So I can to get rid of my old stuff.
The problem is that I haven’t any idea how to delete my old licenses from usb-key and account.
You cannot delete the license. You can only transfer it to another USB-eLicenser or User Account. If you are going to sell your Cunase 7 license, read this article, please.